transmission trouble

[longshot94]

Can a newbie get some help ?

I have a 94 Sentra XE GA16 manual 5sp with high miles. Recently had the transmission rebuilt. After fighting with it a little, me and a friend re-installed it. Curiosity drove us to remove the interlock sleeve and the detent ball (maybe) fell out. Not knowing what it was at the time, we put the sleeve back and filled the car up with fluids.

Then we tested it out. It ran fine, but when changing the gears, it was difficult to get in 2nd gear. Otherwise, the car drove well, so I went with it.

After driving for two weeks, I noticed a grinding noise when idling after a cross-town drive (clutch not pressed down). I knew something is up. The transmission shouldn't go bad 2 wks after a rebuild, right?

Anyway, I drained the transmission oil and there were big chunks of metal on the plug. Any idea what went wrong?